The gland that secretes the hormone calcitonin is the: MCQ with Answer and Explanation

Explanation:
The thalamus is a paired structure forming the main part of the diencephalon, situated above the brainstem. It is often described as the 'gateway to the cerebral cortex'. Its primary function is to act as a major relay station, receiving almost all incoming sensory information (except olfaction) and motor signals from various parts of the body and the brain, processing them, and then projecting them to the appropriate specific areas of the cerebral cortex. It also plays a role in regulating consciousness, sleep, and alertness.

Explanation:
Thrombin converts soluble fibrinogen into insoluble fibrin monomers, which polymerize and cross-link to form a stable blood clot. Fibrinogen is the precursor, prothrombin is the precursor of thrombin. The clotting cascade amplifies the signal.

Explanation:
Vitamin D (calcitriol) stimulates the production of calcium-binding proteins in the intestinal lining, enhancing calcium absorption. Deficiency leads to rickets/osteomalacia. Vitamin A is for vision, C for collagen, B₁₂ for nerve function.